Details for Benchmark: LX2822
N 41° 27.300 W 072° 40.317 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In MIDDLESEX county, CT View Original Datasheet
- E 82
- Marker Type:
- bench mark disk
- in rock outcrop
- Most reliable and expected to hold position/elevation well.
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Documented History (by the NGS)
|1/1/1985 by NGS (MONUMENTED)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1985
2.7 KM (1.7 MI) SOUTH FROM DURHAM. 1.4 KM (0.85 MI) SOUTH ALONG STATE HIGHWAY 17 FROM THE JUNCTION OF STATE HIGHWAY 68 IN DURHAM, THENCE 1.4 KM (0.85 MI) SOUTH ALONG STATE HIGHWAY 79 TO THE MARK ON THE LEFT, 12.34 METERS (40.5 FT) NORTHEAST OF THE CENTERLINE OF THE HIGHWAY, 6.55 METERS (21.5 FT) NORTHWEST OF THE CENTER OF OLD BLUE HILLS ROAD. THE MARK IS ABOVE LEVEL WITH HIGHWAY.
- The horizontal coordinates were scaled from a topographic map and have an estimated accuracy of +/- 6 seconds.
- The orthometric height was determined by differential leveling and adjusted by the National Geodetic Survey in June 1991.
- The geoid height was determined by GEOID99.
- The dynamic height is computed by dividing the NAVD 88 geopotential number by the normal gravity value computed on the Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45 degrees latitude (g = 980.6199 gals.).
- The modeled gravity was interpolated from observed gravity values.